Today's report showing that a significant proportion of new fathers may suffer from postnatal depression - with knock-on effects on the psyche of their offspring - is sure to raise howls of derision. What is wrong with these guys, for goodness sake? It isn't them who just pushed a baby out, is it? It isn't them with the dregs of the epidural and the tempest of hormones crashing out of their bloodstream like credit from the financial system.

And statistically, it isn't them getting forcibly awakened every two-to-three hours, like victims of some fiendish CIA sleep-deprivation technique, to lactate and rock their newborn to sleep. Medically speaking - since we are talking about a scientific study here - surely there is nothing wrong with these fellows that couldn't be cured by the insertion of a backbone into the posterior side of their dorsal cavity, or perhaps a small surgical intervention to stiffen the upper mandible.

Oh, (the argument will go), it wasn't like this in my day. When I was a handsome young father, back in the late palaeolithic, men were men and women were dragged around by the hair. On a need-to-drag basis. We never fretted about the effect of the father's mood on his children. In my day children were lucky if their fathers didn't eat them. Now, let that be an end to this silliness.

Of course, the difference with today's new fathers is that we are more likely to engage in hands-on care for our babies, poor saps that we are. New fatherhood two or three generations ago was typically limited to a spot of pacing outside the maternity ward, the sharing of a cigar with the doctor, and then a five-year wait until little Timmy was old enough to be taught rugger and the art of street fighting. I conducted an unscientific survey recently: the fathers of most of my friends had never changed a nappy. In fairness, a great number of them would have liked to get more involved, but the workplace culture of the day made it nearly impossible. Men worked from dawn till dusk; women stayed at home.

But two of my male friends suffered the genuine psychic agony of depression following the births of their children, and it was pretty messy.

Social patterns have changed and today's dads are more likely to share in the dirty work, to join in the sleep deprivation, to take time off work after the birth, and to provide the kind of psychological support to their partner that might in previous generations have been provided by the neighbourhood mums - who these days are often out working. I realise I used the technical term "psychological support" just now, which is really just a neat medical circumlocution for the process by which the new dad cringes in the corner of the kitchen while his partner throws plates at his head and screams, you bastard, you sperm-laden bastard, this is all your fucking fault, until she feels better.

Mere sleep deprivation, the end of your social life with your mates, the transformation of your much-loved partner into a plate-hurling banshee, the unstemmed flood of emails from work entitled "Sorry to interrupt your paternity leave, but there's a real crisis here...", and the inevitable moving-in of your mother-in-law ... how could these things possibly make a man depressed?

I know: it's a medical mystery. But thank goodness researchers are finally taking it seriously. It's new, this focus from psychiatrists on the father-child relationship. From the time of Piaget (ironically the father of developmental psychology), researchers have concentrated on the mother-and-child as the significant unit in early infancy. They aren't the only profession to react slowly to the growing role of fathers. As a dad who takes a hands-on role in bringing up his pesky infants, I'm amazed at how frequently letters from schools and playgroups and healthcare schemes are addressed "Dear mums". (Actually, I'm amazed how often they're addressed "Dear mum's", but that's a chip on another shoulder.) Last year, I was actually standing in my son's nursery, along with three mothers, to hear the teacher's briefing on some forthcoming poster-paint-related initiative. The teacher looked at us all and said brightly, "Right, mums, let's get started!"

Hands-on fathers of young children are used to being invisible. But it's great that researchers are starting to acknowledge their new role, and to address some of the problems they face. I only hope that word will get out about the good stuff, too, so more men will begin to discover the irresistible fun that comes with getting really involved with their young kids. It's a secret that's been closed to us for too long.